Peat carbon in the Earth system through time

加拿大拥有世界上大部分的湿地。这些生态系统在全新世和更新世时期以泥炭的形式积累了大量的碳库，并且数千年来一直是甲烷（一种强大的温室气体）的重要天然来源。因此，加拿大的湿地以复杂的方式影响着全球碳循环，预计这将随着气候变暖而变化。我的研究计划的总体目标是调查泥炭形成湿地在全球碳气候系统中的作用，从而为加拿大提供关键的新信息，以应对缓解当前和未来气候变化的挑战。拟议的研究计划解决了一系列悬而未决的问题，在湿地古生态科学。第一个问题涉及温带湿地碳库的规模和重要性。高纬度和热带地区的泥炭地在总体碳储量方面是最大的，并且量化得相对较好。温带湿地因人类活动的影响而严重退化，随着湿地被转变为农业、城市或工业用地，面积损失巨大。因此，这项研究将使用最先进的建模技术来预测在人类影响之前，温带地区的古湿地将存在于何处。利用现有的和新的现场数据从残留的湿地在人为景观，估计泥炭深度和碳含量将结合模拟面积范围产生的温带湿地碳库的规模的第一次估计。第二个目标是量化“埋藏”池中的泥炭碳。虽然冰川侵蚀阻止了更新世时期古老泥炭地广泛分布的泥炭碳的持续存在，但由于独特的地理环境，在安大略的远北地区，超过30，000年的泥炭地被保存在冰川沉积物下。使用测年技术，以及宏观和微观化石指标的研究，该研究计划旨在确定泥炭碳在那些时候是如何以及为什么积累的。最后，该计划旨在调查净碳平衡在冰后期的安大略的火圈和邻近的哈德逊湾低地泥炭地。将从这些地区收集泥炭芯，用于分析有壳变形虫（对地下水位深度敏感的微生物）和新的分子指标，这些指标将被整合，以确定随着气候变化和生态演替的推移，碳吸收和释放的速率。这些地区有广泛的泥炭地，可能会受到未来发展的影响。通过一系列的项目将由学员进行，这项研究将提供关键信息，以确定我们的湿地在全球碳循环和气候系统中的重要性。

Canada is home to a large portion of the world's wetlands. These ecosystems have accumulated vast pools of carbon in the form of peat over the Holocene and Pleistocene Epochs, and have also been important natural sources of methane, a potent greenhouse gas, for many thousands of years. Thus, Canada's wetlands affect the global carbon cycle in complex ways, and this is predicted to change with climate warming. The overarching goal of my research program is to investigate the role of peat-forming wetlands in the global carbon-climate system, thus providing Canada with critical new information to face the challenge of mitigating present and future climate change. The proposed research program addresses a series of open questions in wetland paleo-biogeoscience. The first concerns the size and importance of the temperate zone wetland carbon pool. Peatlands in high latitude and tropical regions are the largest in terms of overall carbon storage and are relatively well quantified. Temperate zone wetlands have been severely degraded by human impact, with massive losses in areal extent as wetlands have been converted to agricultural, urban or industrial land uses. Thus, this research will use cutting edge modelling techniques to predict where paleo-wetlands would have existed in temperate zone regions prior to human impact. Using available and new field data from remnant wetlands in anthropogenic landscapes, estimates for peat depth and carbon content will be combined with modelled areal extents to produce the first estimates of the size of the temperate wetland carbon pool. The second objective relates to the quantification of peat carbon in “buried” pools. While glacial erosion has prevented the persistence of widespread peat carbon from ancient peatlands dating to the Pleistocene, there are locations in Ontario's Far North where peatlands >30,000 years old are preserved underneath glacial deposits, owing to unique geographic settings. Using dating techniques, and the study of macro- and micro-fossil indicators, this research program seeks to determine how and why peat carbon accumulated at those times. Finally, this program seeks to investigate net carbon balance over the post-glacial period in peatlands of Ontario's Ring of Fire and adjacent Hudson Bay Lowlands. Peat cores will be collected from these regions for analysis of testate amoebae (micro-organisms sensitive to water table depth) and novel molecular indicators which will be integrated to determine rates of carbon uptake and release over time in response to shifting climates and ecological succession. These are regions with extensive peatlands which may be subject to future development. Through a series of projects to be carried out by student trainees, this research will provide critical information for determining the importance of our wetlands in global carbon cycling and in the climate system.